Light-emitting devices (organic electroluminescent elements) mainly comprise an anode, a cathode, and a light-emitting layer disposed between the anode and the cathode. The light-emitting layer contains a light-emitting material that is an organic compound and emits light by application of voltage across the anode and the cathode.
The organic electroluminescent elements are required to have a wide variety of light-emitting colors as the application fields has been expanding, and light-emitting materials having various light-emitting colors have been developed.
For example, to form a light-emitting layer having a prescribed light-emitting color by a coating method, a technique has been disclosed. The technique uses a light-emitting composite material prepared by mixing three light-emitting materials (light emissive polymers) each having a different light-emitting color at an adjusted mixing ratio (for example, see Patent Document 1).